Abstract: According to the principle of vibration isolation, the structural and dynamic parameters were optimized on the basis of double-layer nonlinear fasteners, and the dynamic deformation, vibration and transmission characteristics of track system were tested respectively by selecting the lines with similar working conditions. The test results showed that the optimized double-layer nonlinear damping fastener could meet the safety requirements of track line. Compared with the original damping fastener, the vertical first-order frequency with the optimized fastener was reduced, the damping increased, and the Z-weighted acceleration total vibration level of the tunnel wall vibration was reduced by 1.7~2.2 dB, which proved that the optimized damping fastener had better vibration isolation effect.